In the United States alone it is estimated that 60,000 people die each year of liver failure, whereas the donor pool remains constant at approximately 4000 with 16-18,000 on the waiting list. The odds of receiving a donor liver for subjects waiting on the list are only 1 in 8, yet there is no effective treatment or prevention available to extend the lifetime of this group of patients.
Liver failure results in multiple organ dysfunction and mortality rates are in the order of 80%. Bacterial-derived toxin and toxic metabolites such as acetaldehyde play key roles in disease pathogenesis. For example, gut-derived endotoxaemia and bacterial translocation play a central role in the pathogenesis of cirrhosis and its complications. However therapeutic options to target these factors are currently limited to long-term antibiotics with the attendant problem of infection with resistant organisms.
Orally administered adsorbent porous carbon particles have been used for centuries for the treatment or prevention of various disorders without any major side effects. Activated carbons are widely used to treat poisoning. A microporous carbon, AST-120 (available under the trade name KREMEZIN® from Kureha Corp., Japan) is used to treat patients with renal failure. However clinical trials evaluating the efficacy of AST-120 in the management of hepatic encephalopathy have proven negative.